a smoky obsidian amulet

A small square amulet of obsidian has been fastened to a dark metal chain. Both the amulet and the chain have been inscribed with jagged, angular runes. A crystal sphere has been inlaid into the middle of the stone. Inside the crystal, clouds of dark smoke shift constantly in a mesmerizing display of dark power.

It is a smoky obsidian amulet.
It radiates a magical aura.
It weighs a few ounces.

You identify a smoky obsidian amulet.
It is a magic, enchanted, and anti-good object.
It weighs four ounces, and it is worth about six celeb and forty-five busc.
Its keywords are amulet, smoky, and obsidian.
It decreases the cast time and mana cost of the darkness spell.